/* body div */
#body{
    border: 1px #000000 dashed;
    width: 600px;
    border-radius: 10px 10px;
    margin: 50px auto 0px;
}

/* head div：首页、登陆、注销 */
#body>div:nth-of-type(1){
    text-align: center;
    line-height: 1;
}

/* head div中的子div1 首页 */
#body>div:nth-of-type(1)>div:nth-of-type(1){
    float: left;
    margin-top: 10px;
    margin-left: 5px;
}

/* head div中的子div2 登陆、注销 */
#body>div:nth-of-type(1)>div:nth-of-type(2){
    float: right;
    margin-top: 10px;
    margin-right: 5px;
}

/* head div中的h3 */
#body>div:nth-of-type(1)>h3{
    clear: both;
    line-height: 3;
}

/* 功能div */
#body>div:nth-of-type(2){
    text-align: center;
    line-height: 2;
}

/* 全局a标签样式 */
a{
    text-decoration: #000000 none;
}
a:visited{
    color: #000000;
}
a:hover{
    border-radius: 3px;
    background-color: cadetblue;
    color: aliceblue;
}

/* foot div */
#body>div:nth-of-type(3){
    font-size: x-small;
    font-family: "JetBrains Mono";
    color: cadetblue;
    text-align: center;
}
